The present invention relates to a rangefinder with an image split prism for a golf course hole, and more particularly to a golf rangefinder capable of conveniently and precisely measuring distance from a target such as a flagstick or a flag in hole through a telescope.
In general, golf is a game in which a golfer checks a distance from a hole and uses a golf club corresponding to his/her own hit distance to hit a ball into the hole with a minimum number of strokes.
At this time, a flagstick having a height of about 2.2 m is in the hole so that a golfer can easily check a distance, a direction, etc. from the hole.
Thus, a technique of measuring a distance based on a general flagstick has been published in Korean Utility Model No. 91-2959, titled ‘Rangefinder for Golf Flagstick,’ which is as follows.
In the conventional range finder, an upper case and a lower case are separately provided and assembled into a main body, holders and supporters are internally protruded from one side of the lower case having one surface formed with a see-through hole, a reflection mirror and a prism mirror are respectively adhered and fixed to the opposite holders, a convex mirror and transparent glass are in closely-contact with and inserted in the supporters, and a transparent microfilm having gradations and baseline numerals is attached to one side of the transparent glass.
However, the foregoing conventional configuration is to align an image of the flagstick with the baseline marked for measuring a distance. As the distance gets longer, the gradations become more compact. Therefore, an error is too large to compare the gradations with the flagstick seen faintly at a long distance, and thus it may be impossible to measure the distance.
To solve these problems, the telescope shown in FIG. 1 may be combined with the reticle 40 having the gradations and the baseline numerals. However, the image is susceptible to hand vibration or the like movement in accordance with magnifications of the telescope, and it is thus difficult to read the gradations corresponding to the size of flagstick.
That is, if the telescope is used as disclosed in Korean Patent Publication No. 10-2001-0084094, the hand vibration or body movement causes a shake of the image to be increased in proportion to the magnification of the telescope, and it is thus difficult to read the gradation by aligning the fixed gradations with the shaking image, thereby decreasing utilization of the range finder due to low accuracy in distance measurement and inconvenience in use.
Meanwhile, a laser rangefinder for measuring a distance based on a laser beam reflected from the flagstick is expensive, whereas it shows high accuracy. Also, a global positioning system (GPS) rangefinder for measuring a distance between a golfer and the center or edge of a green just estimates a distance from the flagstick and has to be inconveniently consistently upgraded.
Accordingly, there is a need of developing a golf rangefinder that is not only inexpensive but also shows high accuracy in distance measurement.